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Mohamed MS, Klann E. Autism- and epilepsy-associated EEF1A2 mutations lead to translational dysfunction and altered actin bundling. Proc Natl Acad Sci U S A 2023; 120:e2307704120. [PMID: 37695913 PMCID: PMC10515156 DOI: 10.1073/pnas.2307704120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/28/2023] [Indexed: 09/13/2023] Open
Abstract
Protein synthesis is a fundamental cellular process in neurons that is essential for synaptic plasticity and memory consolidation. Here, we describe our investigations of a neuron- and muscle-specific translation factor, eukaryotic Elongation Factor 1a2 (eEF1A2), which when mutated in patients results in autism, epilepsy, and intellectual disability. We characterize three EEF1A2 patient mutations, G70S, E122K, and D252H, and demonstrate that all three mutations decrease de novo protein synthesis and elongation rates in HEK293 cells. In mouse cortical neurons, the EEF1A2 mutations not only decrease de novo protein synthesis but also alter neuronal morphology, regardless of endogenous levels of eEF1A2, indicating that the mutations act via a toxic gain of function. We also show that eEF1A2 mutant proteins display increased tRNA binding and decreased actin-bundling activity, suggesting that these mutations disrupt neuronal function by decreasing tRNA availability and altering the actin cytoskeleton. More broadly, our findings are consistent with the idea that eEF1A2 acts as a bridge between translation and the actin cytoskeleton, which is essential for proper neuron development and function.
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Affiliation(s)
- Muhaned S. Mohamed
- Center for Neural Science, New York University, New York, NY10003
- NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY10016
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY10003
- NYU Neuroscience Institute, New York University Langone Medical Center, New York, NY10016
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2
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Navarro-Martínez A, Vicente-García C, Carvajal JJ. NMJ-related diseases beyond the congenital myasthenic syndromes. Front Cell Dev Biol 2023; 11:1216726. [PMID: 37601107 PMCID: PMC10436495 DOI: 10.3389/fcell.2023.1216726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/21/2023] [Indexed: 08/22/2023] Open
Abstract
Neuromuscular junctions (NMJs) are a special type of chemical synapse that transmits electrical stimuli from motor neurons (MNs) to their innervating skeletal muscle to induce a motor response. They are an ideal model for the study of synapses, given their manageable size and easy accessibility. Alterations in their morphology or function lead to neuromuscular disorders, such as the congenital myasthenic syndromes, which are caused by mutations in proteins located in the NMJ. In this review, we highlight novel potential candidate genes that may cause or modify NMJs-related pathologies in humans by exploring the phenotypes of hundreds of mouse models available in the literature. We also underscore the fact that NMJs may differ between species, muscles or even sexes. Hence the importance of choosing a good model organism for the study of NMJ-related diseases: only taking into account the specific features of the mammalian NMJ, experimental results would be efficiently translated to the clinic.
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Affiliation(s)
| | - Cristina Vicente-García
- Centro Andaluz de Biología del Desarrollo, CSIC-UPO-JA, Universidad Pablo de Olavide, Sevilla, Spain
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Mohamed MS, Klann E. Autism- and epilepsy-associated EEF1A2 mutations lead to translational dysfunction and altered actin bundling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.06.543912. [PMID: 37333416 PMCID: PMC10274670 DOI: 10.1101/2023.06.06.543912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Protein synthesis is a fundamental cellular process in neurons that is essential for synaptic plasticity and memory consolidation. Here, we describe our investigations of a neuron- and muscle-specific translation factor, e ukaryotic E longation F actor 1a2 (eEF1A2), which when mutated in patients results in autism, epilepsy, and intellectual disability. We characterize three most common EEF1A2 patient mutations, G70S, E122K, and D252H, and demonstrate that all three mutations decrease de novo protein synthesis and elongation rates in HEK293 cells. In mouse cortical neurons, the EEF1A2 mutations not only decrease de novo protein synthesis, but also alter neuronal morphology, regardless of endogenous levels of eEF1A2, indicating that the mutations act via a toxic gain of function. We also show that eEF1A2 mutant proteins display increased tRNA binding and decreased actin bundling activity, suggesting that these mutations disrupt neuronal function by decreasing tRNA availability and altering the actin cytoskeleton. More broadly, our findings are consistent with the idea that eEF1A2 acts as a bridge between translation and the actin skeleton, which is essential for proper neuron development and function. Significance Statement E ukaryotic E longation F actor 1A2 (eEF1A2) is a muscle- and neuron-specific translation factor responsible for bringing charge tRNAs to the elongating ribosome. Why neurons express this unique translation factor is unclear; however, it is known that mutations in EEF1A2 cause severe drug-resistant epilepsy, autism and neurodevelopmental delay. Here, we characterize the impact of three common disease-causing mutations in EEF1A2 and demonstrate that they cause decreased protein synthesis via reduced translation elongation, increased tRNA binding, decreased actin bundling activity, as well as altered neuronal morphology. We posit that eEF1A2 serves as a bridge between translation and the actin cytoskeleton, linking these two processes that are essential for neuronal function and plasticity.
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Davies FCJ, Hope JE, McLachlan F, Marshall GF, Kaminioti-Dumont L, Qarkaxhija V, Nunez F, Dando O, Smith C, Wood E, MacDonald J, Hardt O, Abbott CM. Recapitulation of the EEF1A2 D252H neurodevelopmental disorder-causing missense mutation in mice reveals a toxic gain of function. Hum Mol Genet 2021; 29:1592-1606. [PMID: 32160274 DOI: 10.1093/hmg/ddaa042] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 12/24/2022] Open
Abstract
Heterozygous de novo mutations in EEF1A2, encoding the tissue-specific translation elongation factor eEF1A2, have been shown to cause neurodevelopmental disorders including often severe epilepsy and intellectual disability. The mutational profile is unusual; ~50 different missense mutations have been identified but no obvious loss of function mutations, though large heterozygous deletions are known to be compatible with life. A key question is whether the heterozygous missense mutations operate through haploinsufficiency or a gain of function mechanism, an important prerequisite for design of therapeutic strategies. In order both to address this question and to provide a novel model for neurodevelopmental disorders resulting from mutations in EEF1A2, we created a new mouse model of the D252H mutation. This mutation causes the eEF1A2 protein to be expressed at lower levels in brain but higher in muscle in the mice. We compared both heterozygous and homozygous D252H and null mutant mice using behavioural and motor phenotyping alongside molecular modelling and analysis of binding partners. Although the proteomic analysis pointed to a loss of function for the D252H mutant protein, the D252H homozygous mice were more severely affected than null homozygotes on the same genetic background. Mice that are heterozygous for the missense mutation show no behavioural abnormalities but do have sex-specific deficits in body mass and motor function. The phenotyping of our novel mouse lines, together with analysis of molecular modelling and interacting proteins, suggest that the D252H mutation results in a gain of function.
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Affiliation(s)
- Faith C J Davies
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Jilly E Hope
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Fiona McLachlan
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Grant F Marshall
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Laura Kaminioti-Dumont
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Vesa Qarkaxhija
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Francis Nunez
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Owen Dando
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Colin Smith
- Academic Department of Neuropathology, Centre for Clinical Brain Sciences, Edinburgh, EH16 4SB, United Kingdom
| | - Emma Wood
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Josephine MacDonald
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Oliver Hardt
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.,Department of Psychology, McGill University, Montreal, QC H3A 1B1, Canada
| | - Catherine M Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
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5
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Translation elongation factor 1A2 is encoded by one of four closely related eef1a genes and is dispensable for survival in zebrafish. Biosci Rep 2021; 40:221899. [PMID: 31950975 PMCID: PMC6997148 DOI: 10.1042/bsr20194191] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 12/14/2022] Open
Abstract
Zebrafish are valuable model organisms for the study of human single-gene disorders: they are genetically manipulable, their development is well understood, and mutant lines with measurable, disease-appropriate phenotypic abnormalities can be used for high throughput drug screening approaches. However, gene duplication events in zebrafish can result in redundancy of gene function, masking loss-of-function phenotypes and thus confounding this approach to disease modelling. Furthermore, recent studies have yielded contrasting results depending on whether specific genes are targeted using genome editing to make mutant lines, or whether morpholinos are used (morphants). De novo missense mutations in the human gene EEF1A2, encoding a tissue-specific translation elongation factor, cause severe neurodevelopmental disorders; there is a real need for a model system to study these disorders and we wanted to explore the possibility of a zebrafish model. We identified four eef1a genes and examined their developmental and tissue-specific expression patterns: eef1a1l1 is first to be expressed while eef1a2 is only detected later during development. We then determined the effects of introducing null mutations into translation elongation factor 1A2 (eEF1A2) in zebrafish using CRISPR/Cas9 gene editing, in order to compare the results with previously described morphants, and with severe neurodegenerative lethal phenotype of eEF1A2-null mice. In contrast with both earlier analyses in zebrafish using morpholinos and with the mouse eEF1A2-null mice, disruption of the eef1a2 gene in zebrafish is compatible with normal lifespan. The resulting lines, however, may provide a valuable platform for studying the effects of expression of mutant human eEF1A2 mRNA.
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González-Cano R, Montilla-García Á, Ruiz-Cantero MC, Bravo-Caparrós I, Tejada MÁ, Nieto FR, Cobos EJ. The search for translational pain outcomes to refine analgesic development: Where did we come from and where are we going? Neurosci Biobehav Rev 2020; 113:238-261. [PMID: 32147529 DOI: 10.1016/j.neubiorev.2020.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/06/2020] [Accepted: 03/04/2020] [Indexed: 12/11/2022]
Abstract
Pain measures traditionally used in rodents record mere reflexes evoked by sensory stimuli; the results thus may not fully reflect the human pain phenotype. Alterations in physical and emotional functioning, pain-depressed behaviors and facial pain expressions were recently proposed as additional pain outcomes to provide a more accurate measure of clinical pain in rodents, and hence to potentially enhance analgesic drug development. We aimed to review how preclinical pain assessment has evolved since the development of the tail flick test in 1941, with a particular focus on a critical analysis of some nonstandard pain outcomes, and a consideration of how sex differences may affect the performance of these pain surrogates. We tracked original research articles in Medline for the following periods: 1973-1977, 1983-1987, 1993-1997, 2003-2007, and 2014-2018. We identified 606 research articles about alternative surrogate pain measures, 473 of which were published between 2014 and 2018. This indicates that preclinical pain assessment is moving toward the use of these measures, which may soon become standard procedures in preclinical pain laboratories.
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Affiliation(s)
- Rafael González-Cano
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Armilla, Granada, Spain.
| | - Ángeles Montilla-García
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Armilla, Granada, Spain.
| | - M Carmen Ruiz-Cantero
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Armilla, Granada, Spain.
| | - Inmaculada Bravo-Caparrós
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Armilla, Granada, Spain.
| | - Miguel Á Tejada
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Armilla, Granada, Spain; IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria.
| | - Francisco R Nieto
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Armilla, Granada, Spain.
| | - Enrique J Cobos
- Department of Pharmacology, Faculty of Medicine, University of Granada, Granada, Spain; Institute of Neuroscience, Biomedical Research Center, University of Granada, Armilla, Granada, Spain; Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain; Teófilo Hernando Institute for Drug Discovery, Madrid, Spain.
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Candidate Genes Associated with Delayed Neuropsychomotor Development and Seizures in a Patient with Ring Chromosome 20. Case Rep Genet 2020; 2020:5957415. [PMID: 32082653 PMCID: PMC6995492 DOI: 10.1155/2020/5957415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 12/17/2019] [Indexed: 11/25/2022] Open
Abstract
Ring chromosome 20 (r20) is characterized by intellectual impairment, behavioral disorders, and refractory epilepsy. We report a patient presenting nonmosaic ring chromosome 20 followed by duplication and deletion in 20q13.33 with seizures, delayed neuropsychomotor development and language, mild hypotonia, low weight gain, and cognitive deficit. Chromosomal microarray analysis (CMA) enabled us to restrict a chromosomal segment and thus integrate clinical and molecular data with systems biology. With this approach, we were able to identify candidate genes that may help to explain the consequences of deletions in 20q13.33. In our analysis, we observed five hubs (ARFGAP1, HELZ2, COL9A3, PTK6, and EEF1A2), seven bottlenecks (CHRNA4, ARFRP1, GID8, COL9A3, PTK6, ZBTB46, and SRMS), and two H-B nodes (PTK6 and COL9A3). The candidate genes may play an important role in the developmental delay and seizures observed in r20 patients. Gene ontology included microtubule-based movement, nucleosome assembly, DNA repair, and cholinergic synaptic transmission. Defects in these bioprocesses are associated with the development of neurological diseases, intellectual disability, neuropathies, and seizures. Therefore, in this study, we can explore molecular cytogenetic data, identify proteins through network analysis of protein-protein interactions, and identify new candidate genes associated with the main clinical findings in patients with 20q13.33 deletions.
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Mild epileptic phenotype associates with de novo eef1a2 mutation: Case report and review. Brain Dev 2020; 42:77-82. [PMID: 31477274 DOI: 10.1016/j.braindev.2019.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 08/07/2019] [Accepted: 08/13/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Mutations in the elongation factor 1 alpha 2 (EEF1A2) gene have been recently shown to cause epileptic encephalopathy (MIM # 616409 EIEE33) associated with neurodevelopmental disorders such as intellectual disability, autistic spectrum disorder, hypotonia and dysmorphic facial features. EEF1A2 protein is involved in protein synthesis, suppression of apoptosis, regulation of actin function and cytoskeletal structure. To date, only sixteen patients with EEF1A2 mutations have been reported. CASE REPORT We described a new case, a boy with severe intellectual disability with absent speech, autistic spectrum disorder, mild dysmorphic facial features, failure to thrive and epilepsy associated to a de novo heterozygous missense mutation in EEF1A2 (c.364G>A; p.Glu122Lys) identified by next generation sequencing; it was already reported in other studies. Most clinical features are shared by all individuals with EEF1A2 mutation, but unlike others reports our patient showed a mild epileptic phenotype: epilepsy developed in late infancy and was well-controlled with antiepileptic drugs. Moreover, at the onset of epilepsy, interictal wake/sleep electroencephalograms showed typical pattern that disappeared with age. CONCLUSION This report focused that EEF1A2 mutations should be considered not only in patients with epileptic encephalopathy, but also in those with less severe epilepsy. A typical EEG pattern may be a biomarker for EEF1A2 mutation, but further investigations and longitudinal clinical observations are required.
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Kapur M, Ackerman SL. mRNA Translation Gone Awry: Translation Fidelity and Neurological Disease. Trends Genet 2018; 34:218-231. [PMID: 29352613 DOI: 10.1016/j.tig.2017.12.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/04/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
Abstract
Errors during mRNA translation can lead to a reduction in the levels of functional proteins and an increase in deleterious molecules. Advances in next-generation sequencing have led to the discovery of rare genetic disorders, many caused by mutations in genes encoding the mRNA translation machinery, as well as to a better understanding of translational dynamics through ribosome profiling. We discuss here multiple neurological disorders that are linked to errors in tRNA aminoacylation and ribosome decoding. We draw on studies from genetic models, including yeast and mice, to enhance our understanding of the translational defects observed in these diseases. Finally, we emphasize the importance of tRNA, their associated enzymes, and the inextricable link between accuracy and efficiency in the maintenance of translational fidelity.
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Affiliation(s)
- Mridu Kapur
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA.
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10
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Biallelic mutations in the gene encoding eEF1A2 cause seizures and sudden death in F0 mice. Sci Rep 2017; 7:46019. [PMID: 28378778 PMCID: PMC5380952 DOI: 10.1038/srep46019] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 03/09/2017] [Indexed: 01/18/2023] Open
Abstract
De novo heterozygous missense mutations in the gene encoding translation elongation factor eEF1A2 have recently been found to give rise to neurodevelopmental disorders. Children with mutations in this gene have developmental delay, epilepsy, intellectual disability and often autism; the most frequently occurring mutation is G70S. It has been known for many years that complete loss of eEF1A2 in mice causes motor neuron degeneration and early death; on the other hand heterozygous null mice are apparently normal. We have used CRISPR/Cas9 gene editing in the mouse to mutate the gene encoding eEF1A2, obtaining a high frequency of biallelic mutations. Whilst many of the resulting founder (F0) mice developed motor neuron degeneration, others displayed phenotypes consistent with a severe neurodevelopmental disorder, including sudden unexplained deaths and audiogenic seizures. The presence of G70S protein was not sufficient to protect mice from neurodegeneration in G70S/- mice, showing that the mutant protein is essentially non-functional.
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Lam WWK, Millichap JJ, Soares DC, Chin R, McLellan A, FitzPatrick DR, Elmslie F, Lees MM, Schaefer GB, Abbott CM. Novel de novo EEF1A2 missense mutations causing epilepsy and intellectual disability. Mol Genet Genomic Med 2016; 4:465-74. [PMID: 27441201 PMCID: PMC4947865 DOI: 10.1002/mgg3.219] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Exome sequencing has led to the discovery of mutations in novel causative genes for epilepsy. One such gene is EEF1A2, encoding a neuromuscular specific translation elongation factor, which has been found to be mutated de novo in five cases of severe epilepsy. We now report on a further seven cases, each with a different mutation, of which five are newly described. METHODS New cases were identified and sequenced through the Deciphering Developmental Disabilities project, via direct contact with neurologists or geneticists, or recruited via our website. RESULTS All the mutations cause epilepsy and intellectual disability, but with a much wider range of severity than previously identified. All new cases share specific subtle facial dysmorphic features. Each mutation occurs at an evolutionarily highly conserved amino acid position indicating strong structural or functional selective pressure. CONCLUSIONS EEF1A2 should be considered as a causative gene not only in cases of epileptic encephalopathy but also in children with less severe epilepsy and intellectual disability. The emergence of a possible discernible phenotype, a broad nasal bridge, tented upper lip, everted lower lip and downturned corners of the mouth may help in identifying patients with mutations in EEF1A2.
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Affiliation(s)
- Wayne W K Lam
- South East of Scotland Clinical Genetics ServiceCrewe RoadEdinburghUK; Centre for Genomic & Experimental MedicineMRC Institute of Genetics and Molecular MedicineUniversity of EdinburghWestern General HospitalCrewe RoadEdinburghEH4 2XUUK; Muir Maxwell Epilepsy CentreUniversity of Edinburgh20 Sylvan PlaceEdinburghEH9 1UWUK; Paediatric NeurosciencesRoyal Hospital for Sick ChildrenSciennes RoadEdinburghEH9 1LFUK
| | - John J Millichap
- Epilepsy Center Departments of Pediatrics and Neurology Ann & Robert H. Lurie Children's Hospital of Chicago Northwestern University Feinberg School of Medicine 225 E Chicago Ave Box #29 Chicago Illinois 60611
| | - Dinesh C Soares
- Centre for Genomic & Experimental MedicineMRC Institute of Genetics and Molecular MedicineUniversity of EdinburghWestern General HospitalCrewe RoadEdinburghEH4 2XUUK; MRC Human Genetics UnitMRC Institute of Genetics and Molecular MedicineUniversity of EdinburghWestern General HospitalCrewe RoadEdinburghEH4 2XUUK
| | - Richard Chin
- Muir Maxwell Epilepsy CentreUniversity of Edinburgh20 Sylvan PlaceEdinburghEH9 1UWUK; Paediatric NeurosciencesRoyal Hospital for Sick ChildrenSciennes RoadEdinburghEH9 1LFUK; Child Life and HealthUniversity of Edinburgh20 Sylvan PlaceEdinburghEH9 1UWUK
| | - Ailsa McLellan
- Paediatric Neurosciences Royal Hospital for Sick Children Sciennes Road Edinburgh EH9 1LF UK
| | - David R FitzPatrick
- Paediatric NeurosciencesRoyal Hospital for Sick ChildrenSciennes RoadEdinburghEH9 1LFUK; MRC Human Genetics UnitMRC Institute of Genetics and Molecular MedicineUniversity of EdinburghWestern General HospitalCrewe RoadEdinburghEH4 2XUUK
| | - Frances Elmslie
- South West Thames Regional Genetics Service St George's Hospital Tooting London UK
| | - Melissa M Lees
- Department of Clinical Genetics Great Ormond Street Hospital Great Ormond Street London UK
| | - G Bradley Schaefer
- Division of Medical Genetics Arkansas Children's Hospital Little Rock Arkansas
| | | | - Catherine M Abbott
- Centre for Genomic & Experimental MedicineMRC Institute of Genetics and Molecular MedicineUniversity of EdinburghWestern General HospitalCrewe RoadEdinburghEH4 2XUUK; Muir Maxwell Epilepsy CentreUniversity of Edinburgh20 Sylvan PlaceEdinburghEH9 1UWUK
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Genome-wide DNA methylation profiles and their relationships with mRNA and the microRNA transcriptome in bovine muscle tissue (Bos taurine). Sci Rep 2014; 4:6546. [PMID: 25306978 PMCID: PMC4194443 DOI: 10.1038/srep06546] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/15/2014] [Indexed: 12/21/2022] Open
Abstract
DNA methylation is a key epigenetic modification in mammals and plays important roles in muscle development. We sampled longissimus dorsi muscle (LDM) from a well-known elite native breed of Chinese Qinchuan cattle living within the same environment but displaying distinct skeletal muscle at the fetal and adult stages. We generated and provided a genome-wide landscape of DNA methylomes and their relationship with mRNA and miRNA for fetal and adult muscle studies. Integration analysis revealed a total of 77 and 1,054 negatively correlated genes with methylation in the promoter and gene body regions, respectively, in both the fetal and adult bovine libraries. Furthermore, we identified expression patterns of high-read genes that exhibit a negative correlation between methylation and expression from nine different tissues at multiple developmental stages of bovine muscle-related tissue or organs. In addition, we validated the MeDIP-Seq results by bisulfite sequencing PCR (BSP) in some of the differentially methylated promoters. Together, these results provide valuable data for future biomedical research and genomic and epigenomic studies of bovine skeletal muscle that may help uncover the molecular basis underlying economically valuable traits in cattle. This comprehensive map also provides a solid basis for exploring the epigenetic mechanisms of muscle growth and development.
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Xu L, Zhao F, Ren H, Li L, Lu J, Liu J, Zhang S, Liu GE, Song J, Zhang L, Wei C, Du L. Co-expression analysis of fetal weight-related genes in ovine skeletal muscle during mid and late fetal development stages. Int J Biol Sci 2014; 10:1039-50. [PMID: 25285036 PMCID: PMC4183924 DOI: 10.7150/ijbs.9737] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Accepted: 08/16/2014] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND Muscle development and lipid metabolism play important roles during fetal development stages. The commercial Texel sheep are more muscular than the indigenous Ujumqin sheep. RESULTS We performed serial transcriptomics assays and systems biology analyses to investigate the dynamics of gene expression changes associated with fetal longissimus muscles during different fetal stages in two sheep breeds. Totally, we identified 1472 differentially expressed genes during various fetal stages using time-series expression analysis. A systems biology approach, weighted gene co-expression network analysis (WGCNA), was used to detect modules of correlated genes among these 1472 genes. Dramatically different gene modules were identified in four merged datasets, corresponding to the mid fetal stage in Texel and Ujumqin sheep, the late fetal stage in Texel and Ujumqin sheep, respectively. We further detected gene modules significantly correlated with fetal weight, and constructed networks and pathways using genes with high significances. In these gene modules, we identified genes like TADA3, LMNB1, TGF-β3, EEF1A2, FGFR1, MYOZ1, and FBP2 correlated with fetal weight. CONCLUSION Our study revealed the complex network characteristics involved in muscle development and lipid metabolism during fetal development stages. Diverse patterns of the network connections observed between breeds and fetal stages could involve some hub genes, which play central roles in fetal development, correlating with fetal weight. Our findings could provide potential valuable biomarkers for selection of body weight-related traits in sheep and other livestock.
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Affiliation(s)
- Lingyang Xu
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China; ; 4. Animal Genomics and Improvement Laboratory, U.S. Department of Agriculture-Agricultural Research Services, Beltsville, Maryland 20705, USA; ; 5. Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland 20742, USA
| | - Fuping Zhao
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Hangxing Ren
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China; ; 2. Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Li Li
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China; ; 3. College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, 625014, China
| | - Jian Lu
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jiasen Liu
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Shifang Zhang
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - George E Liu
- 4. Animal Genomics and Improvement Laboratory, U.S. Department of Agriculture-Agricultural Research Services, Beltsville, Maryland 20705, USA
| | - Jiuzhou Song
- 5. Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland 20742, USA
| | - Li Zhang
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Caihong Wei
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Lixin Du
- 1. National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
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14
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Nakajima J, Okamoto N, Tohyama J, Kato M, Arai H, Funahashi O, Tsurusaki Y, Nakashima M, Kawashima H, Saitsu H, Matsumoto N, Miyake N. De novo EEF1A2 mutations in patients with characteristic facial features, intellectual disability, autistic behaviors and epilepsy. Clin Genet 2014; 87:356-61. [PMID: 24697219 DOI: 10.1111/cge.12394] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 03/24/2014] [Accepted: 04/01/2014] [Indexed: 01/07/2023]
Abstract
Eukaryotic elongation factor 1, alpha-2 (eEF1A2) protein is involved in protein synthesis, suppression of apoptosis, and regulation of actin function and cytoskeletal structure. EEF1A2 gene is highly expressed in the central nervous system and Eef1a2 knockout mice show the neuronal degeneration. Until now, only one missense mutation (c.208G > A, p.Gly70Ser) in EEF1A2 has been reported in two independent patients with neurological disease. In this report, we described two patients with de novo mutations (c.754G > C, p.Asp252His and c.364G > A, p.Glu122Lys) in EEF1A2 found by whole-exome sequencing. Common clinical features are shared by all four individuals: severe intellectual disability, autistic behavior, absent speech, neonatal hypotonia, epilepsy and progressive microcephaly. Furthermore, the two patients share the similar characteristic facial features including a depressed nasal bridge, tented upper lip, everted lower lip and downturned corners of the mouth. These data strongly indicate that a new recognizable disorder is caused by EEF1A2 mutations.
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Affiliation(s)
- J Nakajima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan; Department of Pediatrics, Tokyo Medical University, Shinjuku, Japan
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15
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Camera D, Boase NA, Kumar S, Pow DV, Poronnik P. Subtle gait abnormalities in Nedd4 heterozygous mice. Behav Brain Res 2013; 260:15-24. [PMID: 24280120 DOI: 10.1016/j.bbr.2013.11.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 11/13/2013] [Accepted: 11/14/2013] [Indexed: 11/15/2022]
Abstract
Nedd4 is a widely expressed ubiquitin ligase that is necessary for normal neuronal development and function. However, largely due to the lethality of Nedd4 homozygous knockout mice, little is known about the physiological roles of Nedd4 in the adult brain. In this study we used Nedd4 heterozygous mice, which are viable and live to maturity, to assess for motor function and gait. Global motor function was not altered in these mice, a result consistent with the low level of Nedd4 expression observed in motor neurons of the spinal cord. However, Nedd4 heterozygous mice showed significant age-dependent changes in gait. The gait abnormalities included an overall extension of gait that was only evident in the 6 month old mice. We also observed distinct expression patterns of Nedd4, with pronounced staining in the Purkinje neurons of the cerebellum that are crucial for normal gait, and lower levels in other motor areas of the CNS. It has been recently shown that Nedd4 directly interacts with GluR1 containing AMPA receptors in an activity dependent manner to modulate receptor levels at the post-synaptic membrane. Using confocal immunohistochemistry, we found that there were subtle changes in GluR1 expression in 6 month old Nedd4 heterozygous mice. There appeared to be a redistribution of GluR1 into larger puncta in the molecular layer and in the membrane of the soma of the Purkinje neurons. This study is the first to show that a 50% reduction in Nedd4 levels is sufficient to produce significant gait defects in 6 month old mice. These defects may arise in part, from altered distribution of GluR1 in cerebellar neurons.
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Affiliation(s)
- Daria Camera
- Health Innovations Research Institute, School of Medical Science, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia
| | - Natasha A Boase
- Centre for Cancer Biology, SA Pathology, Frome Road, Adelaide, SA 5000, Australia
| | - Sharad Kumar
- Centre for Cancer Biology, SA Pathology, Frome Road, Adelaide, SA 5000, Australia; Department of Medicine, University of Adelaide, North Terrace, Adelaide, SA 5000, Australia; Division of Health Science, University of South Australia, North Terrace, Adelaide, SA 5000, Australia
| | - David V Pow
- Health Innovations Research Institute, School of Medical Science, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia
| | - Philip Poronnik
- Health Innovations Research Institute, School of Medical Science, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia; School of Medical Sciences and The Bosch Institute, The University of Sydney, Camperdown, NSW 2006, Australia.
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